1. Field of the Invention
The present invention relates generally to barrier systems and, more particularly, to deceleration-limiting barrier systems for decelerating moving objects in a controlled manner.
2. Description of the Related Art
Various types of structures and mechanisms have been employed for decelerating or arresting moving objects. In particular, a number of protective barriers and energy dissipating mechanisms have been devised for arresting a moving vehicle.
At racetracks, for example, protective peripheral barrier walls (especially in the curved portions of the track) are frequently made of rigid materials such as reinforced concrete for the purpose of containing a crash vehicle in order to prevent it from deviating from the raceway and colliding with other objects, or with spectators. Such rigid walls or barriers can cause dangerous levels of deceleration (“G” forces) that may kill or severely injure the driver. Similar results may occur with these rigid barriers on public highways where serious injury or death may result when a motorist deviates from the road and collides with a rigid barrier at high velocity.
Deformable barriers have been employed in some instances to help absorb some of the energy involved in a high-speed collision. For example, “barrel” barriers, which typically consist of several crushable 50-gallon drums positioned side-by-side, provide a degree of protection to vehicles and their occupants during an impact by increasing the distance through which the vehicle is decelerated. Other examples of deformable barriers include stacked vehicle tires and bales of hay. While deformable barriers can lessen the “G” forces involved in a crash, such barriers have generally provided sub-optimal impact absorption. Moreover, deformable barriers can create problems of their own, for example, by “catching” the vehicles that strike them tangentially, leading to more severe damage and injuries than would be the case had the vehicle been permitted to skid along the barrier. In addition, if the vehicle crashes into such a barrier at high speed and is not retained by the barrier, the crashed vehicle and attendant debris can be dangerously thrown back into the path of oncoming vehicles, or into the viewing stands.
Accordingly, there is a need for an improved roadway barrier system and, more specifically, a deceleration-limiting roadway barrier system for decelerating the vehicles in a controlled manner and for retaining moving vehicles that collide with the barrier system.